I don't think it's expectations of sunshine and rainbows that'd disappointing. Even in dark themed stories, readers often want to see some sort of safe space between the MC and ML. Its just what people want. This story is not that. People shouldn't read it if it's not what they like. And with that said I'm gonna let this marinate and see if it gets better later on. Otherwise, this just isn't it for me.
I think people's aren't pissed that there is rape and fighting in a manga about rape and fighting, it's more so that ML was hyped up like a hero who's gonna rescue uke from that rape and fighting but he ended up being similar if not worse than the main villain.
Obviously most people aren't gonna be happy that the only guy who's willing to rescue uke turned out the be the same kinda piece of shit.

Top 10 worst comment sections OAT, idk why yall are reading this story thinking this is some cherry blossoms bullshit. They’re gang affiliated boxers with clear themes of grooming, SA, drugs, etc. guess what? In the real world ur hook up buddy isn’t gonna rock you to sleep and sing lullabies. Especially in the kind of environment they both find themselves in. I’m tired of yall demonizing the tops in these stories of two toxic ppl in a toxic environment. It’s clear most of yall are so heteronormative. This ain’t greys anatomy, it’s a toxic yaoi.